从下拉列表中获取值.(有点棘手） - get value from dropdown. (little tricky)

首先，我对PHP和编码很陌生，但这里是。

我有一个网络表单，它必须从txt文件（位于服务器上的文件夹中）中获取一些信息我学会了如何从文件中获取信息，以及如何制作下拉列表，显示文件夹中的所有文件。我一直想不出如何让它们一起工作，所以它读取的文件名取自下拉列表的选定值。

下拉列表的代码：

<? 
$currentdir = 'files'; //change to your directory 
$dir = opendir($currentdir); 
echo 'Files are as follows:<br>'; 
echo '<select name="select">'; 
while($file = readdir($dir)) 
{ 
    echo '<option value="'.$file.'">'.$file.'</option>'; 
} 
echo '</select>'; 
closedir($dir); ?>

以及从文件中读取的代码：

<input type="text" value="<?php $myFile = ""; $lines = file($myFile); echo $lines[2]; ?>" name="refnr" id="refnr" class="input" />

比方说，下拉列表显示了两个文件，test.txt和test2.txt，如果我从下拉列表中选择test2.txt，我希望它将"test2.txt"放在<?php $myFile = ""的"之间；但无论我如何尝试将代码放入其中以获得选定的值，它都会失败。。。

我的表格的完整代码现在是：

<?php
if (!empty($_POST)) {
    // Used for later to determine result
    $success = $error = false;
    // Object syntax looks better and is easier to use than arrays to me
    $post = new stdClass;
    // Usually there would be much more validation and filtering, but this
    // will work for now.
    foreach ($_POST as $key => $val)
        $post->$key = trim(strip_tags($_POST[$key]));
    // Check for blank fields
    if (empty($post->refnr))
        $error = true;
    else {
        // Get this directory, to include other files from
        $dir = dirname(__FILE__);
        // Get the contents of the pdf into a variable for later
        ob_start();
        require_once($dir.'/pdf.php');
        $pdf_html = ob_get_contents();
        ob_end_clean();
        // Load the dompdf files
        require_once($dir.'/dompdf/dompdf_config.inc.php');
        $dompdf = new DOMPDF(); // Create new instance of dompdf
        $dompdf->load_html($pdf_html); // Load the html
        $dompdf->render(); // Parse the html, convert to PDF
        $pdf_content = $dompdf->output(); // Put contents of pdf into variable for later
        // Get the contents of the HTML email into a variable for later
        ob_start();
        require_once($dir.'/html.php');
        $html_message = ob_get_contents();
        ob_end_clean();
        // Load the SwiftMailer files
        require_once($dir.'/swift/swift_required.php');
        $mailer = new Swift_Mailer(new Swift_MailTransport()); // Create new instance of SwiftMailer
        $message = Swift_Message::newInstance()
                       ->setSubject('Felanmalan') // Message subject
                       ->setTo(array('mymail@hidden' => 'Fel')) // Array of people to send to
                       ->setFrom(array('mymail@hidden' => 'Fel')) // From:
                       ->setBody($html_message, 'text/html') // Attach that HTML message from earlier
                       ->attach(Swift_Attachment::newInstance($pdf_content, 'Felanmalan.pdf', 'application/pdf')); // Attach the generated PDF from earlier
        // Send the email, and show user message
        if ($mailer->send($message))
            $success = true;
        else
            $error = true;
    }
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <meta http-equiv="content-type" content="text/html; charset=utf-8" />
    <title>Felanm&auml;lan fr&aring;n IKEA</title>
    <style type="text/css">
        html, body, h1, h2, h3, h4, h5, h6, p, span, ul, li, div, form, input, select, textarea, button {margin:0; padding:0;}
        ul {list-style:none;}
        a, a:hover {text-decoration:none; outline:0;}
        a img {border:0;}
        body {font:12px/16px Verdana, Arial, sans-serif; background:#ffffff;}
        #container {width:450px; margin:10px auto; padding:10px; overflow:hidden; border:1px solid #000; border-radius:10px; -moz-border-radius:10px; -webkit-border-radius:10px; background:#F9F9F9;}
        #container h1 {margin-bottom:20px; font-size:40px; line-height:40px; font-family:'HelveticaNeue-Light', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-weight:normal;}
        .message {margin-bottom:10px; padding:5px;}
        .success {color:#4F8A10; border:1px solid #4F8A10; background:#DFF2BF;}
        .error {color:#D8000C; border:1px solid #D8000C; background:#FFBABA;}
        label {display:block; margin-bottom:3px; cursor:pointer;}
        .input, textarea, select, button {display:block; width:440px; margin-bottom:10px; padding:3px; font:22px/22px 'HelveticaNeue-Light', 'Helvetica Neue', Helvetica, Arial, sans-serif; border:1px solid #CCC; border-top-width:2px;}
        textarea {font-size:13px; line-height:16px;}
        select {width:396px;}
        button {float:right; width:auto; margin-bottom:0; padding:3px 30px; cursor:pointer; font-size:16px; border:1px solid #999; border-bottom-width:2px; border-radius:5px; -moz-border-radius:5px; -webkit-border-radius:5px; background:#EEE;}
        button:active {border-bottom-width:1px; padding:4px 30px 3px; background:#E9E9E9;}
    </style>
</head>
<body>
<? 
$currentdir = 'files'; //change to your directory 
$dir = opendir($currentdir); 
echo 'Files are as follows:<br>'; 
echo '<select name="select">'; 
while($file = readdir($dir)) 
{ 
    echo '<option value="'.$file.'">'.$file.'</option>'; 
} 
echo '</select>'; 
closedir($dir); ?>
    <div id="container">
        <h1><img src="felimg.png" />  Felanm&auml;lan</h1>
        <?php if ($success) { ?>
            <div class="message success">
                <h4>Congratulations! It worked! Now check your email.</h4>
            </div>
        <?php } elseif ($error) { ?>
            <div class="message error">
                <h4>Sorry, an error occurred. Try again!</h4>
            </div>
        <?php } ?>
        <form method="post" action="">
            <label for="date"><b>Date:</b></label>
            <input type="text" readonly name="date" id="date" class="input" value="<? print(Date("Y-m-d")); ?>"/>
            <label for="refnr"><b>Referensnummer:</b></label>
            <input type="text" value="<?php $myFile = ""; $lines = file($myFile); echo $lines[2]; ?>" name="refnr" id="refnr" class="input" />
            <label for="bestav"><b>Best&auml;lld av:</b></label>
            <input type="text" name="bestav" id="bestav" class="input" />           
            <label for="tel"><b>Tel:</b></label>
            <input type="text" name="tel" id="tel" class="input" />
            <label for="email"><b>Email:</b></label>
            <input type="text" name="email" id="email" class="input" />         
            <label for="kund"><b>Kund:</b></label>
            <textarea name="kund" id="kund" rows="4" cols="40"></textarea>
            <label for="ktel"><b>Tel:</b></label>
            <input type="text" name="ktel" id="ktel" class="input" />
            <label for="art"><b>Ber&ouml;rd Artikel:</b></label>
            <textarea name="art" id="art" rows="3" cols="40"></textarea>
            <label for="fel"><b>Fel p&aring; varan: </b></label>
            <textarea name="fel" id="fel" rows="2" cols="40"></textarea>
            <label for="q1"><b>Installation gjord av fackman:</b></label>
            <select name="q1" id="q1">
                <option value="Ja">Ja</option>
                <option value="Nej">Nej</option>
            </select>
            <label for="q2"><b>Serviceverkstad:</b></label>
            <input type="text" name="q2" id="q2" class="input" />
            <label for="q3"><b>Servicenr:</b></label>
            <input type="text" name="q3" id="q3" class="input" />
            <label for="q4"><b>Serienr:</b></label>
            <input type="text" name="q4" id="q4" class="input" />
            <label for="q5"><b>Inom garanti eller reklamation:</b></label>
            <select name="q5" id="q5">
                <option value="Garanti">Garanti</option>
                <option value="Reklamation">Reklamation</option>
            </select>
            <label for="q6"><b>Informerat om punkt 8:</b></label>
            <select name="q6" id="q6">
                <option value="Ja">Ja</option>
                <option value="Nej">Nej</option>
            </select>           
            <label for="q7"><b>Har kund sj&auml;lv g&aring;tt igenom manual f&ouml;r fels&ouml;kning:</b></label>
            <select name="q7" id="q7">
                <option value="Ja">Ja</option>
                <option value="Nej">Nej</option>
            </select>               
            <label for="q8"><b>Ordernr:</b></label>
            <input type="text" name="q8" id="q8" class="input" />
            <label for="q9"><b>Ink&ouml;psdatum:</b></label>
            <input type="date" name="q9" id="q9" class="input" /><br>

            <p><button type="submit">Submit!</button></p>
        </form>
    </div>
</body>
</html>

希望这是有意义的，如果这是一个愚蠢的问题，我很抱歉：）我已经用了两天的时间在谷歌上搜索和测试，我只是到了需要再次朝着正确的方向努力的地步。

提前谢谢。

p.s简单解释一下我的目标是什么，然后我有一个网络表单，它生成一个txt文件并将其保存在服务器上，然后是另一个表单，"管理员"可以从下拉列表中选择文件，获取客户端在txt版本中填写的信息，然后填写他需要填写的内容，然后将其保存并以PDF格式发送给技术人员。

您可以使用

echo '<select id="select" name="select">'; 
while($file = readdir($dir)) 
{ 
    echo '<option value="'.$file.'">'.$file.'</option>'; 
} 
echo '</select>';

在它被加载到DOM之后，使用

document.getElementById('select').onchange=changeSelect;
function changeSelect(){
    document.getElementById('refnr').value=document.getElementById('select').value;
}
changeSelect();

请在此处查看：http://jsfiddle.net/7nzBS/

I wanted it to put "test2.txt" in between the "" at `<?php $myFile = ""`

您不能做这样的事情，因为"text2.txt"在客户端，$myfile，php变量在服务器端。如果你想从服务器端访问客户端的数据，你需要通过HTTP发送数据。所以你有两个选择：

通过HTTPpost或get发送所选值
通过AJAX发送所选值

感谢Oriol，它起了作用：）

代码现在看起来是这样的，并且正在按我需要的方式工作。也感谢所有其他建议，可爱的快速和有用的回复：）

            <label for="refnr"><b>Referensnummer:</b></label>
        <input type="text" value="<?php $selectedfile = @$_POST['file2']; $myFile = "files/$selectedfile"; $lines = file($myFile); echo $lines[0]; ?>" name="refnr" id="refnr" class="input" />